Understanding Rare Diseases: Where to Start

A rare disease diagnosis changes everything in an instant — but knowledge can restore a sense of agency. Here’s what we wish we’d known from day one.

What counts as “rare”?

In the United States, a disease is classified as rare if it affects fewer than 200,000 people. In Europe, the threshold is 1 in 2,000. Despite sounding small, rare diseases collectively affect an estimated 300 million people worldwide.

Where to start your research

• NORD — National Organization for Rare Disorders, with a detailed disease database
• Orphanet — European rare disease encyclopedia
• Global Genes — patient advocacy and community
• RareConnect — patient communities organized by condition

Practical first steps

1. Request all your medical records in writing
2. Seek a second (or third) opinion — rare disease diagnosis is notoriously difficult
3. Look for a specialist center or academic medical center with experience in your condition
4. Connect with a patient advocacy organization specific to your diagnosis

You are not alone

One of the most isolating things about rare disease is the feeling that no one around you understands. Communities like ours exist to change that.